Display screen or portion thereof with transitional graphical user interface



FIG. 1 is the first image in a sequence for a display screen or portionthereof with transitional graphical user interface showing our newdesign according to a first embodiment;

FIG. 2 is the second image thereof;

FIG. 3 is the third image thereof;

FIG. 4 is the first image in a sequence for a display screen or portionthereof with transitional graphical user interface showing our newdesign according to a second embodiment;

FIG. 5 is the second image thereof;

FIG. 6 is the third image thereof;

FIG. 7 is the first image in a sequence for a display screen or portionthereof with transitional graphical user interface showing our newdesign according to a third embodiment;

FIG. 8 is the second image thereof;

FIG. 9 is the third image thereof;

FIG. 10 is the first image in a sequence for a display screen or portionthereof with transitional graphical user interface showing our newdesign according to a fourth embodiment;

FIG. 11 is the second image thereof;

FIG. 12 is the third image thereof;

FIG. 13 is the first image in a sequence for a display screen or portionthereof with transitional graphical user interface showing our newdesign according to a fifth embodiment;

FIG. 14 is the second image thereof; and,

FIG. 15 is the third image thereof.

The appearance of the transitional image sequentially transitionsbetween the images shown in FIGS. 1-3, 4-6, 7-9, 10-12, and 13-15,respectively. The process of period in which one image transitions toanother image forms no part of the claimed design.

CLAIM The ornamental design for a display screen or portion thereof withtransitional graphical user interface, as shown and described.